Semiconductors are generally fabricated using a layering process on a wafer substrate. This layering process may include imaging, deposition, etching, doping, and cleaning. The deposition step may be performed by Chemical Vapor Deposition (CVD). CVD is a chemical process used to produce high-purity, high-performance solid materials. In a typical CVD process, the substrate is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through a reaction chamber.